Reaction of allyl ethers with aldehydes to produce ketones



Patented July 17, 1951 2,560,770

UNITED STATES PATENT QFFICE 1 REACTION OF ALLYL ETHERS WITH ALDE- HYDES TO PRODUCE KETONES Elbert C. Ladd, Passaic, N. J assignor to United States Rubber Company, New York, N. Y., a corporation of New Jersey No Drawing. Original application November 9, I 1946, Serial N0. 708,929- Divided and this ap plication August 9, 1949, Serial No. 109,413

4 Claims. (01. zen- 594) 1 This invention relates to improvements in the methallyl ether, diallyl formal, acrolein ethyl manufacture of ketones. acetal, 2-acetoxy-methyl allyl acetate, allyl ace- This application i a di f my Copend n tate, allyl ethyl carbonate, allyl caproate, allyl application Serial No. 708,929, filed November laurate, methallyl benzoate, crotyl acetate, cinn- 9, 1946, which issued as Patent No. 2,533,944 on 5 amyl acetate, 2-ch1oroa1ly1 butyrate, methallyl December 12, 1950. 'carbamate, methallyl ethyl sulfate, N-allyl It is known (U. Patent 5,362) that phthalimide, N-allyl acetamide, 3-nitropropene- When Vinyl ompounds Such as Vinyl acetate are 1, allyl triethyl ilicate, methallyl dimethyl phosheated together with aliphatic aldehydes, polyphate, etc. meric products result which are gummy or resin- The preferred Z-propenyl compounds are those ous materials. In contrast, I have found that of the formula R'CH= H X h r R, when non-hydrocarbon Z-propenyl compounds R." and X areas above defined, since these types having the essential linkage are more easily available.

- Any of the conventional sources of free radi- 1 cals such as ultra-violet light,may be employed in the method of my invention, altgiough peroxare reacted under free-radical conditions (e. g., gg f ggjg fi g fgifig g gg g i 52222 3 m the presence of fi radmals aind/or tertiary-butyl hydroperoxide, among others, are stances capable of y 1e1dmg free radlcals) wlth advantageous in commercial scale operations and a non-emc non-tertiary hydrocarbon aldehyde are consequently preferred 5 containing only carbon hydrogen and oxygen 'The above formula for the final product in that W defined ketones may 2 F the illustrative equation represents the 1:1 prodthe chief product. The expression non-enlc not, 1 mole of aldehyde to 1 mole of the is used to exclude ethylenic and acetylenic aldepr0peny1-c0mpound which constitutes a substan s The expression non-tertiary hydrocar tial proportion by weight of the reaction product. 22% gsgi f g group free of The reaction product may also include higher The reaction of my invention is illustrated by boning ketones of the type the tollowing equation: R O RGHO+R'CH=C(R)-CHXY Bi, HXY

radical where n is an integer greater than 1.

RCO CH(R/) CH(R")*OHXY Appreciable quantities of the compounds of where R is' non-tertiary hydrocarbon; R is the latter type can be obtained from the reaction hydrogen, methyl, halomethyl, or halogen; R" of aldehydes with readily polymerizable 2-prois hydrogen, alkyl, aryl, halogen, haloalkyl, or 'penyl compounds such as 2-propeny1 esters of acyloxymethyl; X is nitrogen, oxygen, or halopolybasic acids, e; g., diallyl phthalate, dimethgen; Y is hydrogen or oxygen; or X and Y toallyl fumarate and diallyl succinate, and 2-progether is oxygen. Halo and halogen refer to 40 penyl esters of unsaturated m noar xylic halogen atoms having an atomic weight less acids, e. g., allyl acryla a. h behavior, 1 than 40, that is, chlorine and fluorine. ever, is not generally characteristic of all 2-, More specifically, R may be represented by propenyl compounds containing one or more admethyl, ethyl, propyl, butyl, aniyl, hexyl, isoditional olefinic linkages since others, such as propyl, isobutyl, sec.-amyl, cyclopentyl, cyclodiallylether and diallyl formal, react with aldehexyl, phenyl, and functionally aliphatic radihydes to yield largely the ,one-to-one ketonic cals such as phenylethyl, phenylmethyl, etc. products. v 1 Representative aldehydes are acetaldehyde, The reaction of my invention is carried out by propionaldehyde, butyraldehyde, isobutyraldeheating amixture of the aldehyde, the 2-propeny1 hyde, heptaldehyde, cyclohexanal, benzaldehyde, compound and the peroxide in the presence or ab phenylacetaldehyde, etc. sence of-an inert diluent, and at temperatures suf Illustrative of suitable 2-propenyl com-pounds ficient to decompose the peroxidic compound, and are allyl alcohol, methallyl chloride, 2-chlorowhich are generally in the range of from 0 C. to

methyl a lyl hl ri e, llyl chl ride. allyl ethyl approximately140Q In the case ofthe morevolaether, allyl furfuryl ether, allyl octyl eth ditile aldehydes d 2- p n 1 comnmmrk th m;

more convenient.

actions may be carried out under superatmospheric'pressures.

greater isparticularly desirable for the reaction 1 of aldehydes with the above-mentioned readily polymerizable 2-propenyl compounds, in order to minimize polymerization andother side reactions,

which deleteriously afiect'th yieldof the desired ketones. In cases where it may prove inconvenient or impractical tofen'iploya large excess of the aldehyde reactant, theZ-properiyl compound can be added incrementally to the reaction mixture whereby a substantial excess .of the aldehyde is in effect maintained throughout a major por tion of the reaction period. V

The amount of the peroxidic compound employed as a source of free radicals in my invention varies with the nature-of the reactants as well as withthe reaction conditions, but amounts in'the range of from 1 to'15 moletpercent of the -2- -p'ro- ,penyl compound;g are normally sufiicient. JWhen reaction times are protracted it is often "desirable -to add the peroxide portionawise throughout the -reaction to ensure the presence/of .an adequate concentration of free radicals"in-the'reactiorimixture atalltimes The reaction is carried out until ais'ubstantial conversion of the 2-propenyl' compound to the L -desired ketone is'secured. The reaction'is then halted by cooling, andthe unreactedstarting material are removed by evaporationzunder diminishedpressure. The desired ketoneTmay be then of very high-boiling products, fractional crystallization from thereaction mixture. may prove ally distilled inf'yafci'io to yie1d"9318"'parts or 3- butyropropyl acetate; b. pt. Ill-114 C./11 mm. 1 =1.4311, d4 =0.9805.

Analysis Found: C, 63.8%; H, 9.18%; Theory: C, 62.7%; H, 9.37%.

N t ifi le '3 A solution of 78.5 parts of acrolein ethyl acetal in 450 parts of n-butyraldehyde is heated at 75 C. and atmospheric pressure for 37 hours during :which'time 22.5 parts of dibenzoyl peroxide are *addedin five equal portions. The reaction is completed by heating for 16 additional hours and yieldsiafter evaporation of the unreacted starting xmaterials,'."34.5 parts of the diethylacetal of 3 -butyropropionaldehyde by fractional distilla- 1' tion; b. pt. 10l4 C./6 mm.; =1.4352.

Analysis 11 Found: c. 65.83%; H, 10.96%;

' "Theory: 0, 65.36%; H, 10.97%.

. Examples I v v To a mixture of 86 parts" of 'Z-a cetoxymethyl- 'allyl'acetate and 3 0 parts of n'-butyraldehyde at 76 C, and atmospheric pressure are added 18 parts ofdibenzoyl peroxide in four, approxirnat ely equal, portions in the course of 51 hours.

-The reaction is completed by heating 8 hours "more; and after removal of." the unreacted' start- "ing materials yields by fractional 'disti1lation 45 a recovered by fractional}distillation. :In the case The following exe pl s uiscicse my invention in more detail, all parts being by weight:

.A'Vmixtureof 110' parts-of allyl acetate, '500 parts of acetaldehyde, and-8 parts of dibenzoyl peroxide, is heatedin'an-autoclave of 1200 ml. capacity for about 48 hour at-about 70 C.:'Aft'er coolingto roomtemperature,- the reaction mixtur is Y 10mth ifll t lavekthey acted allyl acetate and acetaldehyde are distilled off, and the residue i s fractionally; distilled in vacuo to yield 82.5' parts'bf 3-acetopropyl acetate as the major component of the reaction product; b. pt. 66.567 C ./3 mm.; 1 9= ;1. 021;- saponification 1 equivalent 144;.7; 2,4-dinitrophenylhydrazone,'m.pt.77.5-78 C- 4 Repetition-of the reaction at 90 C using amixture of100 parts of allyl acetate, .176 -parts::0f acetaldehydeandZA-parts of dibenzoyl peroxide yields '91 parts of 3-aceto-propyl-acetate in '2 hours. c

The esteris readily convertedto the vitamin B1 intermediate, 3-chloro-3-acetopropyl acetate by chlorination.

' 7 Example 2 To a mixture of 132' parts of'allyl acetate and 954 parts of'n-butyraldehyde at 80 C. are added 6.3 parts of dibenzoyl peroxide and after heating for -20hours at atmospheric pressure an additional "63 parts of per'oxide'are added. Thereaction' is completed by heating 28 hours more,

after which the unreacted' starting materials are removed by distillation: and theresidue fraction- Analysis-'- Found: C, 60.09% H, 8.42%; Theory: C, 59.00%; H, 8.25%.

Example 5 To a suctio of 93 partsof diallyl ether in 720 parts of n butyraldehyde at C. and atmosph'ericlpressure are added 19 parts of dibenzoyl peroxide in fourfap proxim'atel'y equal, portions during aperiod'of 32 hours; Thereactionmix- 'ture is further heated for 16 hours, after which unrea'cted starting materials are'distilled off and the residue is fractionally distilled to yield 28 -parts of j3-butyropropyl allyl ether; b. pt. 96 8* C-./6' mm,;, 2u=1.4539. I

A a s a Found: C, 70.31%; H, l0.5f7%;

Theory: C, 70.5%; H, 10.6%.

p Example 6 "Amixture of 128 parts of diallyl formal, 720 parts of n-butyraldehyde and 4.4 parts ofdibenzoyl peroxide is heated at approximately 75 .C; and atmospheric pressure for 10 hours at. which"time"an additional 5 parts of peroxide areintroduced into the reaction mixture. -Heating iscontinued for 10 hours when 5 parts more of peroxide are added and heating is then carried out for ,an additional -10 hours. Fractional distillation flof the reaction mixtureyields some unrea'cted starting materials together with 13 partsgof, 3-butyropropyl vallyloxymethyl ether; b..'.pt. 78-81 CL/l mm.; =1.4447.

Analysis-- V V I Found: C, 65.40%; H, 7.68%; Theory: C, 66.0% H, 10.0%. It's'hould be noted that the reaction of poly-2- propenyl compounds with aldehydes according to my invention, as illustrated above in Examples 5 and 6, yields predominantly the unsaturated ketones, even when a considerable excess of the aldehyde is present in the reaction mixture. The diketones from the reaction of 2 moles of aldehyde with 1 mole of the dipropenyl compound are obtained only in minor amounts, if at all.

The various ketones of this invention, including those which are herein new, may be used inter alia as intermediates in chemical synthesis in the prdouction of dyes, perfumes, and pharmaceuticals.

Although my invention has been particularly described as applied to z-propenyl compounds containin as the hetero atom either oxygen, nitrogen or halogen, the invention may also be applied to 2-propenyl compounds containing other hetero atoms, particularly silicon, phosphorus and sulfur. Exemplary of such compounds are ethyl 2-propenylphosphonate, allyl triethyl silane and methallyl ethyl sulfide.

While I have shown and described various embodiments of the invention, it is to be understood that the invention is susceptible to those modifications which appear within the spirit of the invention and the scope of the appended claims.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

l. The process of preparing ketones which comprises reacting an allyl ether with an aldehyde of the formula RCHO where R is hydrocarbon having the carbon atom which is directly attached to the CH0 selected from the class consisting of primary and secondary carbon atoms. in the presence of a peroxidic catalyst until the desired ketone is formed, and isolating said ketone.

2. The process of preparing ketones which comprises reacting a primary aliphatic aldehyde having the type formula RCHO in which R is a saturated linear hydrocarbon radical with an allyl ether in the presence of a peroxidic catalyst until the desired ketone is formed and isolating said ketone.

3. The process of preparing ketones which comprises reacting a primary aliphatic aldehyde having the type formula RCHO in which R is a saturated straight-chain hydrocarbon radical with an allyl ether in the presence of a peroxidic catalyst until the desired ketone is formed, and isolating said ketone.

4. The process of preparing ketones which comprises reacting a primary aliphatic aldehyde having the type formula R-CHz-CHO in which R is from the class consisting of hydrogen, and saturated straight-chain hydrocarbon radicals, with an allyl ether in the presence of a peroxidic catalyst until the desired ketone is formed and isolating said ketone.

ELBERT C. LADD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,395,292 Peterson et a1. Feb. 19, 1946 2,411,158 Hanford Nov. 19, 1946 2,440,801 Hanforcl et a1. May 4, 1948 

1. THE PROCESS OF PREPARING KETONES WHICH COMPRISES REACTING AN ALLYL ETHER WITH AN ALDEHYDE OF THE FORMULA RCHO WHERE R IS HYDROCARBON HAVING THE CARBON ATOM WHICH IS DIRECTLY ATTACHED TO THE CHO SELECTED FROM THE CLASS CONSISTING OF PRIMARY OF A PEROXIDIC CATALYST ATOMS. IN THE PRESENCE OF A PEROXIDIC CATALYST UNTIL THE DESIRED KETONE IS FORMED, AND ISOLATING SAID KETONE. 